The present invention concerns a mechanism adapted to house applicances which require very little power to work in use and the using time of which is transient, for example, door bells, which mechanism is manually driven to produce the requisite electricity for use.
In view of the incessantly increasing population and shrinking energy source of the world, it is predictable that the seriousness of energy crisis will only change from bad to worse in the future few years. Under such circumstance, it is critically urgent to decrease our reliance upon conventional fossil fuels.
In fact, in some appliances which consume little power because they are devised to work only momentarily rather than continuously in use, for example door bells, can be energized manually, easily, and conveniently by the user himself to bring it into work without the need for a power source, thus expelling the extra accessories such as wire and plug, or batteries, saving the consumption of cells, and obviating the trouble or replacing exhausted cells. Such devices adapt best to those places where necessities are scant due to poor transportation.
Yet known means operated manually by the user to convert his strength into available potential energy stored in mechanical devices within a transient while, and then release the energy for use within a short moment fall into two categories. The function of the first class is accomplished by compressing a spring or the like, and then releasing it to exploit the energy stored therein. Since spring resumes very fast, the period it works is too short for practical use. Although the period of work can be prolonged by mechanically connecting the spring with a accelerating gear train transmitting the motion to a relatively heavy, terminal flywheel whereby the rate of resumption of the spring is reduced in view of the relationship between mass and acceleration: F=ma, when the spring resumes it unstressed position, the flywheel still possess considerable inertia, which however is not practically available since the further rotation results in the stretching of the spring which, unless mechanically disconnected with the gear train immediately after it has reached its equilibrium point, will inevitably countervail the momentum of the flywheel and give rise to considerable loss in the available energy stored in the form of the inertia therein. In this case the spring is first stretched to an extent due to the inertia of the flywheel after passing its equilibrium point, and then retracts and forces the flywheel to counter-rotate. Needless to say, in the damping process, much available energy is lost.
Another class is found in friction drive toys, which is basically in common with the gyrobus in terms of their driving system involving a rapidly spinning flywheel. The ordinary manner to play with such toy by rubbing its wheels vigorously against a flat plane however, is not adapted to be applied to doorbells. Although the flywheel can be energized by rocking a crank arm connecting to the first gear of the accelerating gear train, this method is not altogether satisfactory since the crank arm appears unsightly and clumsy at door. Moreover, the manner clamping the crank arm to rock it does not coincide with ordinary habit by pushing a button or pulling a cord.
Accordingly, it is the object of the present invention to provide an improved gyro-type manually energizing mechanism to obviate and mitigate the aforesaid disadvantages.
According to an aspect of this invention the foregoing disadvantages are overcome by means of a detachable transmission mechanism which is preferably positioned between the first gear of the accelerating train gears and the device through which the force is exerted to effect the engagement and disengagement thereof, thereby exploiting the residual kinetic energy stored in the flywheel in the form of inertia.
These objects of this invention will be accompanied by embodiments as referred to in relation with the annexed drawing of this invention as following.